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A Palette of Fluorescent Aβ42 Peptides Labelled at a Range of Surface-Exposed Sites

Thacker, Dev LU ; Bless, Mara LU ; Barghouth, Mohammad LU ; Zhang, Enming LU and Linse, Sara LU (2022) In International Journal of Molecular Sciences 23(3).
Abstract

Fluorescence-based single molecule techniques provide important tools towards understanding the molecular mechanism of complex neurodegenerative diseases. This requires efficient covalent attachment of fluorophores. Here we create a series of cysteine mutants (S8C, Y10C, S26C, V40C, and A42C) of Aβ42, involved in Alzheimer’s disease, based on exposed positions in the fibril structure and label them with the Alexa-fluorophores using maleimide chemistry. Direct stochastic optical reconstruction microscopy imaging shows that all the labelled mutants form fibrils that can be detected by virtue of Alexa fluorescence. Aggregation assays and cryo-electron micrographs establish that the careful choice of labelling position minimizes the... (More)

Fluorescence-based single molecule techniques provide important tools towards understanding the molecular mechanism of complex neurodegenerative diseases. This requires efficient covalent attachment of fluorophores. Here we create a series of cysteine mutants (S8C, Y10C, S26C, V40C, and A42C) of Aβ42, involved in Alzheimer’s disease, based on exposed positions in the fibril structure and label them with the Alexa-fluorophores using maleimide chemistry. Direct stochastic optical reconstruction microscopy imaging shows that all the labelled mutants form fibrils that can be detected by virtue of Alexa fluorescence. Aggregation assays and cryo-electron micrographs establish that the careful choice of labelling position minimizes the perturbation of the aggregation process and fibril structure. Peptides labelled at the N-terminal region, S8C and Y10C, form fibrils independently and with wild-type. Peptides labelled at the fibril core surface, S26C, V40C and A42C, form fibrils only in mixture with wild-type peptide. This can be understood on the basis of a recent fibril model, in which S26, V40 and A42 are surface exposed in two out of four monomers per fibril plane. We provide a palette of fluorescently labelled Aβ42 peptides that can be used to gain understanding of the complex mechanisms of Aβ42 self-assembly and help to develop a more targeted approach to cure the disease.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Amyloid formation, Imaging, Optical spectroscopy
in
International Journal of Molecular Sciences
volume
23
issue
3
article number
1655
publisher
MDPI AG
external identifiers
  • scopus:85123692402
  • pmid:35163577
ISSN
1661-6596
DOI
10.3390/ijms23031655
language
English
LU publication?
yes
id
0a39ff0a-3bb1-454e-9a15-27f18505bae3
date added to LUP
2022-03-25 11:45:26
date last changed
2024-04-18 06:19:27
@article{0a39ff0a-3bb1-454e-9a15-27f18505bae3,
  abstract     = {{<p>Fluorescence-based single molecule techniques provide important tools towards understanding the molecular mechanism of complex neurodegenerative diseases. This requires efficient covalent attachment of fluorophores. Here we create a series of cysteine mutants (S8C, Y10C, S26C, V40C, and A42C) of Aβ42, involved in Alzheimer’s disease, based on exposed positions in the fibril structure and label them with the Alexa-fluorophores using maleimide chemistry. Direct stochastic optical reconstruction microscopy imaging shows that all the labelled mutants form fibrils that can be detected by virtue of Alexa fluorescence. Aggregation assays and cryo-electron micrographs establish that the careful choice of labelling position minimizes the perturbation of the aggregation process and fibril structure. Peptides labelled at the N-terminal region, S8C and Y10C, form fibrils independently and with wild-type. Peptides labelled at the fibril core surface, S26C, V40C and A42C, form fibrils only in mixture with wild-type peptide. This can be understood on the basis of a recent fibril model, in which S26, V40 and A42 are surface exposed in two out of four monomers per fibril plane. We provide a palette of fluorescently labelled Aβ42 peptides that can be used to gain understanding of the complex mechanisms of Aβ42 self-assembly and help to develop a more targeted approach to cure the disease.</p>}},
  author       = {{Thacker, Dev and Bless, Mara and Barghouth, Mohammad and Zhang, Enming and Linse, Sara}},
  issn         = {{1661-6596}},
  keywords     = {{Amyloid formation; Imaging; Optical spectroscopy}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{3}},
  publisher    = {{MDPI AG}},
  series       = {{International Journal of Molecular Sciences}},
  title        = {{A Palette of Fluorescent Aβ42 Peptides Labelled at a Range of Surface-Exposed Sites}},
  url          = {{http://dx.doi.org/10.3390/ijms23031655}},
  doi          = {{10.3390/ijms23031655}},
  volume       = {{23}},
  year         = {{2022}},
}